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2 sheets sheet l' (No Model C. A. EISENHART.Y DENTAL ELECTRIC APPARATUS.

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C. A. EISENHART.

DENTAL ELECTRIC APPARATUS.

(No Model.)

Patented Aug.28, 1888.

IJV ENTOR,

fk5, Homey UNITED STATES PATENT Ottica@ CHARLES AUGUSTUS EISENHART, OF YORK, PENNSYLVANIA.

DENTAL ELEGTRiC APPARATUS.

SPECIFICATION forming part of Letters Patent No. 388,482, dated August 28, 1898.

Application filed January 3, 1888. Serial No. 259,630. (No model.)

To all whom, it may concern.-

Be it known that I, CHARLES AUGUSTUS EISENHART, a citizen of the United States, residing at York, inthe county of York and State of Pennsylvania, have invented certain new and useful Improvements in Dental Electric Apparatus; and I do hereby declare the following to be a full, clear, and exact description ofthe invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to dental electric apparatus for relieving` the suffering occasioned by the extraction of teeth and for facilitating an examination of the mouth, and is an improvement ou the apparatus described in a patent issued to me on November 24, 1885, numbered 331,121.

The object of the invention is to render the apparatus easier to control and give ita wider range of use.

To these ends my invention consists in certain features of construction, which will be hereinafter fully set forth in the specification, and then definitely indicated in the appended claims.

In the accompanying drawings, Figure I is an elevation of my apparatus, the front of the casing being removed. Fig. 2 is a view in per speetive. looking from the rear of the apparatus, showing the mouth-lamp, the handelectrodes, the forceps, and their circuit-connections. ,Fig. 3 is a detached view of the automatic vibrator or rheotome. Fig. 4 is a detail View of acircuit-closer usedin the primary circuit. Figs. 5 and Gare detail views ofthe devices for connecting the forceps in the secondary circuit and a rheostat for varying the induced current.

In a suitable casing, 1, are placed two or more cells of battery, 2 3. I prefer for this purpose one of the cells to be adapted for opencircuit work and the other to maintain the current at a sufficient degree of constancy for maintaining atineandeseence for short periods a small mouth-lamp. The Leclanch and bichromate batteries would answer well for these respective requirements. The poles of battery 2 are connected with bindingposts 25, secured to the under side of the top 25, beingin metallic connection with the pivotal bearing 27 of a switch, 28. The switch 2S has sufficient play between two stop-pins to enable it to be thrown on or off the contact t6, Fig. 2. Post 2i is in circuit through conductor 2G with one terminal of the primary of an inductioncoil, 42, and contact 46 is connected by a con ductor with a spring, 80, secured to the casing. This springhas secured toits undersidea piece of insulating material, 32, Fig. 4, and when in its normal position another contact-spring,3l, bears upon this insulating material. Spring 3l is in circuit with the other terminal of the primary of the induction-coil through conductor 33. A rocking-bar, 8S, is hung from the casing in operative relation to the spring 30, and when the bar is depressed to the right of its pivot spring 30 is bent down, and,actiug upon spring 31, forces its free end ol'f the insulating spot and causes it to make a scraping Contact with the end of spring 30. The sccondary of the induction-coil is connected to binding-posts 34 35, whence proceed through holes 36 37 in the back ofthe casing conductA ors leading to dischargers or hand-electrodes 49 50. The latter in use are secured to the arms of a dental chair, as set forth in my patent above referred to.

One end of the lever 3S is slotted at 39, and a pin on a vertical rod, S, projects through the slot. This rod is supported so as to slide up and down in bearings 9 and I0 and one in the top of the casing. The rod is pivotally secured at its lower end to a footlever, Il, the latter heilig pivoted at a point, l5, within the easing and having a projecting treadle ou which the foot may bear to depress rod S. A spring, 12, co-operates with the rod, so as to hold it in vertical position when it is free to respond to the resilience ol the spring. A thumbscrew, 16, projects through the easing and can be adjusted in the support 9, so as to hold the rod at any point of depression. Above the top of the casing the rod is provided with an adj ustablc collar, I8, which rcgulates the degree of depression of the rod. Lever 3S carries a pin, 40, ou its other arm, which pin co-operates with a slot in an extensionpiece ou a metallic tube, 4l, arranged to slide freely over the core of the inductioircoil. The function of the slots in lever SS and the magnetic shield is to compensate for the movement of the ends over an arc of a circle.

Frietionally secured to rod S is a frame, et

IOO

,of said extension.

5 6, carrying a rigid strip of insulating material, on which the zines for the constantcurrent battery-cell are supported. The portion 6 of this frame projects through a slot in the side of the casing, (shown in Fig. 2.) and has pivoted to its outer extremity at 1S a clamping-lever, 17. By turning this clamping-lever to the position shown in Fig. l the frame will belocked to the side of the casing, and will remain stationary, irrespective of the movements of the red 8. Suitable bindingposts connected, respectively, with the posi tive and negative elements of battery 3 are secured to the casing, whence connection is made by conductors 19 20 with binding posts 21 22 on the outside ot' the case. The mouthlamp 4S is placed in circuit with these binding-posts through multiple conductor 23.

In order to render the rheotome of the inductioncoil readily accessible for adjustment, I provide the core ofthe coil with a polar extension, 43, extending toward the front of the apparatus, and the vibrator and back stop 44 and 45, faced with platinum at the strikingpoints, as usual, are suitably mounted in front An additional advantage resulting from this arrangement is that the increase ofthe mass of iron at the pole renders the instrument operative with weaker currents, so that a single cell of battery can be relied upon to operate the rheotome, even when the battery is partially polarized.

In some cases it may be desired to introduce the high-tension .current furnished by the induction-coil or the battery-current itself into the muscles around the tooth during the extraction ofthelatter. Forthis purposeIuse the attachment shown in Figs. 2, 5, and G, in which 5l is a removable adjustable rhcostat provided with a hook, 59, for hanging it to the handelectrode 50. Surrounding the hook, and in electric connection therewith, is a switch, 60, adapted to be moved over a set of contacts, 6l 62 63 64, &e., to vary thev number of coils in circuit, and consequently the resistance of said circuit, in a manner that will be evident to those familiar with the art. lIhe device shown in Fig. G is adapted to clamp a handle of the dental forceps 5ft when the clip is attached, and ring 58 is forced into the position shown in Fig. 2, and the forceps may be removed by slipping the ring back into the position shown in Fig. 6.

The operation of the apparatus will now be understood. Incase a cavity of a tooth or any part of the mouth is to be examined, the lampcurrent is thrown on by pressing the button ll ou rod 8 with the hand or foot or by treading on the foot-lever. This carries the frame 4 5 6 bearing the zines down into the excitingfluid, where it may be locked during the examination by the set-screw 1G acting on the rod or by the clamp 17. XVhen the examination is concluded, the rod is released and the zines raised out of the excitant by spring l2, and then may be locked in an elevated posi tion by the clamp 17, which leaves the apparatus free for use during the extracting operation, during which the zines will be held up irrespective of any shifting of rod 8. rPhe de= pression of rod 8 closes the circuit at springs 30 3l; but as it is open at the switch 2S the primary circuit through the induction coil will not be closed until this switch is thrown into engagement with contact 4G-in other words, the primary circuit is open normally at two points, contact at one point being controlled by the rod 8 and at the other by switch 28. The handswitch may be used when the rod is depressed to its full limitand the shield over the core is raised to its highest point. The shield is then in position to permit the greatest strength of induced current to be devcloped in the secondary circuit, and byshifting the switch this current may be developed or stopped at will. It will thus be seen that currents of different tensions may be induced in the secondary circuit by depressing the rod to different degrees, the shield 4l being raised frcm the core a distance proportional to the amount of said depression.

By shifting the switch-arm of the rhcostat to different contacts the induced current may be varied in intensity within wide limits, as a different resistance is thrown into the induced circuit for every successive contact to which the switch may be turned. It will be observed that the rhcostat is located in the forceps branch of the therapeutic circuit,and it should be so placed whether the primary or the induced current is administered, as when located at this portion of the circuit it attemperates the effect on the muscles in electric connection with that branch toa greater degree than if placed in a part of the circuit remote from said muscles. If, for example, this coil were hung on distributing-electrode 49, the shock would be ameliorated for the muscles of the hand in contact with said electrode, while the muscles of the mouth would receive relatively a much more severe contraction.

By "distributing-electrodes7 in this case I mean the conductors which introduce the current into the body of the patient, and so call them to avoid confusion with the term electrode77 as a definitive of the element of a battery.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. The combination of a vertically-movable rod, a spring for normally holding said rod elevated, a lever acted upon by the rod, an inA duction-coil provided with a regulator cou trolled by the lever, a circuit-closer in the primary circuit in operative relation te the lever, and a lock for engaging the rod and holding it at any degree of depression.

2. The combination of a sliding rod, au adjustable collar for regulating the degree of thrust of said rod, an inductioircoil, and regulating devices therefor controlled by said rod.

3. The combination of a sliding rod,battery elements carried thereby and frictionally se- IIO cured thereto, and a locking device for maintaining the elements in a fixed position, whereby the rod may be reciprocated independently of the elements.

4. The combination of a sliding rod,battery elements carried by said rod, an electric lamp, circuit-connections between the elements and lamp, a second circuit, a circuit-closer therein actuated by a movement of the rod, an induction-coil in said second circuit, a regulator for the induced current controlled by the rod, and means for locking the rod when shifted.

5. In a dental apparatus, the combination of a battery inductioncoil and rheotome, distributing-electrodes outside the instrument in the secondary circuit, a circuit-closer in the primary circuit, a lampcircuit electric lamp connected therewith by flexible connections, and a circuitcloser for controlling the lampcircuit.

6. The combination of metallic spring 30, provided with an insulated spot on one face thereof, metallic spring 3l, co-operating with spring 30 and normally bearing on the insulated spot, and a push-piece for forcing the springs together, whereby a scraping contact may be made with Ithe metal adjacent to the spot.

7. The combination ofasourceofelectricity, a distributing-electrode in circuit with one pole thereof, a pair of dental forceps, and a clip in circuit with the other pole7 said clip being provided with gripping-jaws to engage the handle of the forceps, and means for locking` the jaws in engagement with the handle.

8. In a dental electric apparatus, the combination of an electric conductor provided at its terminals with distributing electrodes adapted to convey the current to a patient to be operated upon, a resistance-coil in circuit to with said conductor near one of the terminals to moderate the effect of the curi-ent on the part ofthe body to which the said terminal is applied, and a connector for connecting and disconnecting one of the electrodes to said conductor.

9. In a dental electric apparatus, the combination of a generator of electricity, an electric circuit, a distributiiig-electrode at one circuit-terminal, a pair of dental forceps at the 5o other circuitterminal, and an adjustable rheostat in the forceps branch, as and forthe purpose set forth.

l0. In a dental electric apparatus, the coinbination of ageneratorof electricity, aninduction-coil, primary and secondary circuits, a distributing-electrode at one secondary terminal, a pair of dental forceps at the other secondary terminal, andan adjustable resistance` coil in the secondary circuit, as and for the 6o purpose set forth.

l1. In a dental electric apparatus, the combination of an electric circuit, adistribntingelectrode in said circuit ifor conveying the current to the patient to be operated upon, and a resistance'coil in juxtaposition with said electrode to moderate the effect of the current on the portion of the patients body to which said electrode is applied, for thepurpose set forth.

In testimony whereof I affix my signature in 7o presence of two witnesses.

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W'itnesses:

S. M. GABLE, GEO. B. Karima. 

